The HD-73 rotor incorporates all features that contribute to strength, durability and ease of installation without special tools or equipment as well as simple foolproof operation of the control box. The HD-73 rotator is constructed of heavy duty aluminum castings selected for their excellent strength capability and favorable weight characteristic, contributing to ease of erection and resistance to severe wind and adverse weather conditions that exist throughout the world. The HD-73 unit is factory lubricated with a lifetime high quality lubricant that will withstand temperature ranges of 120° Fahrenheit to —20° Fahrenheit. The HD-73 mast support bracket design permits a centering procedure for in-tower application without shims or difficult trial and error adjustments and the base design permits easy four bolt in-tower mounting without spacers. The mast support bracket design also provides a positive drive no-slip option. The HD-73 rotator unit has two full raceways of 100 ball bearings which give it excellent balanced weight bearing capacity. The HD-73 has an improved automatic brake action for simplified operating procedure which also reduces risk of antenna damage by sudden stops imposing high inertia stresses on the antenna, tower and rotator. *1 The i iD-73 has the heaviest pitch gear teeth (steel hardened) of any rotator in its size and price range. The HD-73 control unit features TWO-SPEED rotation with one five-position switch. This presents a one revolution per minute speed for rotating over an extended arc and a slower speed for adjustment of, say, several degrees one way or the other for fine adjustments for the best signal on receiving and transmitting. The rotator not only has a readily accessible externally located fuse for total unit protection, it also has an internally mounted automatic reset thermal protector for the motor and transformer against shorts or possible connection error or prolonged operation. A large, back-illuminated 3V2" Weston D’Arsonval, Taut Band, linear, full scale, 90° swing meter is calibrated in bold S-W-N-E-S as well as a degree-graduated scale. I he meter direction indicating voltage supply is solid state voltage regulated for meter indication accuracy regardless of wide line voltage or load variation; the regulating range is 105 to 129 volts. The HD-73 rotor was designed to operate antennas with a maximum of 10.7 square feet of wind load area when properly installed.